Job Vacancy Network Architect (DV Security Clearance)
Chippenham
CGI
Published on 09/14/2026
Share this job
CGI’s Space, Defence and Intelligence business unit designs, builds and operates secure, mission-critical systems across defence, intelligence, aerospace, maritime and space. We combine deep technical expertise with leading technology partners to deliver complex infrastructure and cyber solutions.
CGI was recognised in the Sunday Times Best Places to Work List 2025 and has been named a UK ‘Best Employer’ by the Financial Times. We offer a competitive salary, excellent pension, private healthcare and a share scheme (3.5% + 3.5% matching), making you a CGI Partner rather than simply an employee.
This role is based on-site near Chippenham, five days per week. Due to the secure nature of the programme, you must hold UK Security Clearance.
Candidate profile
As a Network Architect, you will define and assure secure, resilient network architectures across physical, virtual and software-defined infrastructure, with a strong focus on VMware NSX-T/NSX and network virtualisation.
You will design NSX networking solutions covering logical switching and routing, overlay/underlay integration, Tier-0/Tier-1 gateways, Edge services, segmentation, micro-segmentation and distributed firewalling. You will ensure effective integration between NSX, physical networks, VMware infrastructure and Kubernetes/VKS platforms.
Working across infrastructure, security and engineering teams, you will provide technical leadership throughout design, build and integration, ensuring solutions meet performance, availability, resilience and security requirements.
Key responsibilities:
• Design end-to-end physical, virtual and software-defined network architectures.
• Define VMware NSX-T/NSX architecture, including segments, overlays, Tier-0/Tier-1 gateways and Edge services.
• Design routing, switching, firewalling, VPN and secure connectivity solutions.
• Define segmentation and micro-segmentation using NSX Distributed Firewall (DFW).
• Integrate NSX with physical infrastructure, VMware and Kubernetes/VKS environments.
• Define resilient network architectures, redundancy and failover.
• Resolve complex routing, traffic-flow, latency, capacity and performance challenges.
• Embed security-by-design and zero-trust principles.
• Produce HLDs, LLDs, network diagrams and technical design documentation.
• Provide technical assurance through architecture and design reviews.
Required qualifications to be successful in this role
You will have strong network architecture experience within complex infrastructure environments, ideally within Defence or National Security, with particular expertise in VMware NSX-T/NSX and virtual networking.
Essential experience:
• Strong VMware NSX-T/NSX architecture and design experience.
• Strong understanding of software-defined networking and network virtualisation.
• Experience with NSX logical switching/routing, Tier-0/Tier-1 gateways and Edge architectures.
• Experience with NSX DFW, segmentation and micro-segmentation.
• Strong understanding of overlay/underlay networking and physical/virtual network integration.
• Strong knowledge of TCP/IP, VLANs, BGP, VPNs and routing technologies.
• Network security architecture, including firewalls, zero trust and encrypted connectivity.
• Kubernetes networking experience, ideally including VKS.
• High availability, resilience, redundancy and failover design.
• Ability to produce high-quality HLDs, LLDs and architecture diagrams.
• Strong technical leadership and stakeholder communication skills.
Desirable
• NSX Federation and multi-site architecture.
• VMware Cloud Foundation (VCF).
• EVPN/VXLAN.
• Kubernetes CNI and network policy.
• Infrastructure as Code using Terraform or Ansible.
• NSX/API-based network automation.
• Network monitoring and observability.
• SD-WAN and load-balancing technologies.
• Relevant VMware, networking or security certifications.
#LI-SB2
You will design NSX networking solutions covering logical switching and routing, overlay/underlay integration, Tier-0/Tier-1 gateways, Edge services, segmentation, micro-segmentation and distributed firewalling. You will ensure effective integration between NSX, physical networks, VMware infrastructure and Kubernetes/VKS platforms.
Working across infrastructure, security and engineering teams, you will provide technical leadership throughout design, build and integration, ensuring solutions meet performance, availability, resilience and security requirements.
Key responsibilities:
• Design end-to-end physical, virtual and software-defined network architectures.
• Define VMware NSX-T/NSX architecture, including segments, overlays, Tier-0/Tier-1 gateways and Edge services.
• Design routing, switching, firewalling, VPN and secure connectivity solutions.
• Define segmentation and micro-segmentation using NSX Distributed Firewall (DFW).
• Integrate NSX with physical infrastructure, VMware and Kubernetes/VKS environments.
• Define resilient network architectures, redundancy and failover.
• Resolve complex routing, traffic-flow, latency, capacity and performance challenges.
• Embed security-by-design and zero-trust principles.
• Produce HLDs, LLDs, network diagrams and technical design documentation.
• Provide technical assurance through architecture and design reviews.
Required qualifications to be successful in this role
You will have strong network architecture experience within complex infrastructure environments, ideally within Defence or National Security, with particular expertise in VMware NSX-T/NSX and virtual networking.
Essential experience:
• Strong VMware NSX-T/NSX architecture and design experience.
• Strong understanding of software-defined networking and network virtualisation.
• Experience with NSX logical switching/routing, Tier-0/Tier-1 gateways and Edge architectures.
• Experience with NSX DFW, segmentation and micro-segmentation.
• Strong understanding of overlay/underlay networking and physical/virtual network integration.
• Strong knowledge of TCP/IP, VLANs, BGP, VPNs and routing technologies.
• Network security architecture, including firewalls, zero trust and encrypted connectivity.
• Kubernetes networking experience, ideally including VKS.
• High availability, resilience, redundancy and failover design.
• Ability to produce high-quality HLDs, LLDs and architecture diagrams.
• Strong technical leadership and stakeholder communication skills.
Desirable
• NSX Federation and multi-site architecture.
• VMware Cloud Foundation (VCF).
• EVPN/VXLAN.
• Kubernetes CNI and network policy.
• Infrastructure as Code using Terraform or Ansible.
• NSX/API-based network automation.
• Network monitoring and observability.
• SD-WAN and load-balancing technologies.
• Relevant VMware, networking or security certifications.
#LI-SB2
Working environment
Together, as owners, let’s turn meaningful insights into action.
Life at CGI is rooted in ownership, teamwork, respect and belonging. Here, you’ll reach your full potential because…
You are invited to be an owner from day 1 as we work together to bring our Dream to life. That’s why we call ourselves CGI Partners rather than employees. We benefit from our collective success and actively shape our company’s strategy and direction.
Your work creates value. You’ll develop innovative solutions and build relationships with teammates and clients while accessing global capabilities to scale your ideas, embrace new opportunities, and benefit from expansive industry and technology expertise.
You’ll shape your career by joining a company built to grow and last. You’ll be supported by leaders who care about your health and well-being and provide you with opportunities to deepen your skills and broaden your horizons.
That same commitment to fairness extends to how we use technology. To support our recruitment team, AI tools may be used to help assess applications though they never replace human judgement. All hiring decisions remain entirely in the hands of our recruitment professionals.
Come join our team—one of the largest IT and business consulting services firms in the world.
Life at CGI is rooted in ownership, teamwork, respect and belonging. Here, you’ll reach your full potential because…
You are invited to be an owner from day 1 as we work together to bring our Dream to life. That’s why we call ourselves CGI Partners rather than employees. We benefit from our collective success and actively shape our company’s strategy and direction.
Your work creates value. You’ll develop innovative solutions and build relationships with teammates and clients while accessing global capabilities to scale your ideas, embrace new opportunities, and benefit from expansive industry and technology expertise.
You’ll shape your career by joining a company built to grow and last. You’ll be supported by leaders who care about your health and well-being and provide you with opportunities to deepen your skills and broaden your horizons.
That same commitment to fairness extends to how we use technology. To support our recruitment team, AI tools may be used to help assess applications though they never replace human judgement. All hiring decisions remain entirely in the hands of our recruitment professionals.
Come join our team—one of the largest IT and business consulting services firms in the world.
London, England, United Kingdom
> 1000 employees
IT services
We are a global business with 91,500 professionals across hundreds of locations worldwide, providing end-to-end IT and business process services that drive our clients’ businesses. In the UK alone, we have around 6,000 member-partners working across 19 towns and cities, doing everything from writing complex code to designing sophisticated software solutions. The work we do powers some of the most ambitious projects that touch the lives of many.
Our approach sets us apart, characterised by our proximity model, international presence, expertise, and operational excellence. We organise our operations within metro markets where our clients have concentrated footprints, empowering our local teams to build trusted, in-person relationships. As you build your career here, you’ll develop your skills, share your insights, and work side-by-side with colleagues and clients on innovative solutions that address the most complex issues.
Our commitment to ownership, flexibility, and being approachable makes us easy to do business with. Join us, and together, as owners, let’s turn meaningful insights into action to meet the needs and balance the interests of our clients, shareholders, communities, and each other.
Benefits:
- Insurance coverage
- Medical benefits
- Pension plan
- Member Assistant Programme
- Check4Cancer
- Flexible time off
- Share Purchase Plan
- Member discounts
- Dental benefits
- Vision benefits
- Profit Participation Plan
- Health and Wellbeing Programme
Apply to this job!
Find your next job from +8,000 jobs!
Manage your visibility
Salary, remote work... Define all the criteria that are important to you.
Get discovered
Recruiters come directly to look for their future hires in our CV library.
Join a community
Connect with like-minded tech and IT professionals on a daily basis through our forum.
Network Architect (DV Security Clearance)
CGI